This invention relates to a reinforced sleeve coupled to a frame assembly so as to increase the structural strength and stiffness of the frame at selected locations. More particularly, the invention relates to a sleeve coupled to the pillar portion of an automobile frame, wherein the sleeve supports a reinforcing medium that becomes chemically active and expands in response to a predetermined change in ambient conditions.
For many years the automobile industry has been concerned with designing improved vehicle body structures that absorb or deflect impact loads imposed on the vehicle at or near the passenger compartment. While reinforcing the surfaces surrounding the vehicle passenger compartment has long been practiced in the automotive industry, often the structures used to reinforce the frame surrounding the passenger compartment include metal components. These metal reinforcement members tend to add unwanted weight to the automobile. In other instances, the reinforcing members include complex configurations that require welding or mechanical fasteners to affix the reinforcement member to the frame.
Consequently, there is needed a lightweight, easily installed apparatus for reinforcing the automobile frame structure, particularly in the area of the passenger compartment.
An object of the present invention is to define a reinforcing sleeve that enhances the capacity of an automobile frame assembly to dissipate energy from an impact load imposed on the vehicle frame to avoid deformation of the frame in special locations.
To accomplish this and other objects, there is provided a sleeve including a carrier and a reinforcing, medium supported by the carrier. The carrier is fabricated from a polymeric material, and includes an interior and exterior surface.
The reinforcing medium extends along at least a portion of the length of the exterior of the carrier. The reinforcing medium is an epoxy-based resin. Preferably the reinforcing medium is a heat-activated structural foam that expands upon heating, typically by a foaming reaction. The preferred reinforcing materials are structural foams available from LandL Products of Romeo, Mich. under the designations L5206, L5207, L5208 and L5209.
The sleeve is formed by (1) providing a carrier; (2) reinforcing the carrier by applying a reinforcing medium thereto; and (3) heating the reinforcing medium to a temperature sufficient to cause the reinforcing medium to expand and adhere to adjacent surfaces, either via a bonding formulation in the reinforcing medium itself or via a separate adhesive layer.
A general method for installing the sleeve in a frame member includes (1) providing a carrier having a hollow portion; (2) coupling the sleeve to the carrier; and (3) heating the energy absorbing medium to a temperature sufficient to cause the reinforcing medium to expand, such as via activation of a blowing agent.
In one embodiment, the sleeve is coupled to a pillar portion of an automobile frame. The sleeve is received in the hollow portion of the pillar frame, wherein the sleeve includes a carrier and an reinforcing medium supported by the carrier. The reinforcing medium extends along at least a portion of the length of the carrier, and becomes chemically activated upon heating the foam to its thermal activation temperature.